Disk Performance Degrades from RH7.3 -> FC2

[Mike McMullen]

Hi all,

I am trying to figure out a performance degradation in disk i/o after doing a
fresh install of FC2 on a server that previously ran RH7.3.

I have an old ASUS board with a 700MHZ Athalon,
768MB of RAM and 2 Maxtor 60GB drives.

The drives are configured for s/w RAID mirroring and have three
partitions - /boot, swap, / .

Under RH7.3 hdparm would report between 250-270MB of buffered
cache read/sec and 32-39MB/sec buffered disk reads for each drive.

After doing a clean install of FC2 and updating I get the following for
each drive:


/dev/hdd1:
 Timing buffer-cache reads:   672 MB in  2.01 seconds = 334.38 MB/sec
 Timing buffered disk reads:   82 MB in  3.01 seconds =  27.26 MB/sec

/dev/hda1:
 Timing buffer-cache reads:   664 MB in  2.00 seconds = 331.55 MB/sec
 Timing buffered disk reads:   74 MB in  3.03 seconds =  24.46 MB/sec


The good news is the improvement in the buffered-cache reads!

The bad news is the slowdown in buffered disk reads.

Output of  hdparm for each is as follows:

/dev/hda:
 multcount    = 16 (on)
 IO_support   =  1 (32-bit)
 unmaskirq    =  1 (on)
 using_dma    =  1 (on)
 keepsettings =  0 (off)
 readonly     =  0 (off)
 readahead    = 256 (on)
 geometry     = 65535/16/63, sectors = 120103200, start = 0

/dev/hdd:
 multcount    = 16 (on)
 IO_support   =  1 (32-bit)
 unmaskirq    =  1 (on)
 using_dma    =  1 (on)
 keepsettings =  0 (off)
 readonly     =  0 (off)
 readahead    = 256 (on)
 geometry     = 65535/16/63, sectors = 120103200, start = 0

Output of hdparm -i for each drive is as follows:

/dev/hda:

 Model=Maxtor 6Y060L0, FwRev=YAR41VW0, SerialNo=Y2RD8V4E
 Config={ Fixed }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57
 BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=16
 CurCHS=4047/16/255, CurSects=16511760, LBA=yes, LBAsects=120103200
 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes:  pio0 pio1 pio2 pio3 pio4
 DMA modes:  mdma0 mdma1 mdma2
 UDMA modes: udma0 udma1 udma2 udma3 *udma4 udma5 udma6
 AdvancedPM=yes: disabled (255) WriteCache=enabled
 Drive conforms to: (null):

 * signifies the current active mode

/dev/hdd:

 Model=Maxtor 6Y060L0, FwRev=YAR41VW0, SerialNo=Y2RD3XME
 Config={ Fixed }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57
 BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=16
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=120103200
 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes:  pio0 pio1 pio2 pio3 pio4
 DMA modes:  mdma0 mdma1 mdma2
 UDMA modes: udma0 udma1 udma2 udma3 *udma4 udma5 udma6
 AdvancedPM=yes: disabled (255) WriteCache=enabled
 Drive conforms to: (null):

 * signifies the current active mode

There were no h/w changes or bios settings done between RH7.3 and FC2. All I did was
install FC2. I did use the same software raid devices from 7.3 when configuring in disk druid
and just reformatted them.

Can anyone give me any insight as to why the slowdown and how to correct it. I've
googled this but didn't find any settings that seem to help.

Any help appreciated!

Mike